Reproduction patterns among non‐Hodgkin lymphoma survivors by subtype in Sweden, Denmark and Norway: A population‐based matched cohort study

Previous studies concerning reproductive patterns among non‐Hodgkin lymphoma (NHL) survivors are scarce and those available have reported conflicting results. Treatment regimens vary considerably between aggressive and indolent NHL and studies of reproductive patterns by subtypes are warranted. In this matched cohort study, we identified all NHL patients aged 18–40 years and diagnosed between 2000 and 2018 from the Swedish and Danish lymphoma registers, and the clinical database at Oslo University Hospital (n = 2090). Population comparators were matched on sex, birth year and country (n = 19 427). Hazard ratios (HRs) were estimated using Cox regression. Males and females diagnosed with aggressive lymphoma subtypes had lower childbirth rates (HRfemale: 0.43, 95% CI: 0.31–0.59, HRmale: 0.61, 95% CI: 0.47–0.78) than comparators during the first 3 years after diagnosis. For indolent lymphomas, childbirth rates were not significantly different from comparators (HRfemale: 0.71, 95% CI: 0.48–1.04, HRmale: 0.94, 95% CI: 0.70–1.27) during the same period. Childbirth rates reached those of comparators for all subtypes after 3 years but the cumulative incidence of childbirths was decreased throughout the 10‐year follow‐up for aggressive NHL. Children of NHL patients were more likely to be born following assisted reproductive technology than those of comparators, except for male indolent lymphoma patients. In conclusion, fertility counselling is particularly important for patients with aggressive NHL.